Accumulators are devices that store energy in the form of fluid under pressure. Accumulators are useful tools in developing efficient hydraulic systems due to their ability to store excess energy and release it when needed. The accumulators can be used to provide various functions in hydraulic systems. These functions include leakage compensation, pulsation and shock absorption, noise elimination, and load counter-balance.
Traditional accumulators for electro-hydraulic actuators are the nitrogen gas loaded type. These accumulators are generally thought to consist of an elastic membrane charged with nitrogen to provide the potential energy to the hydraulic fluid to operate the actuators. The elastic membranes deteriorate over time, resulting in the nitrogen leaking into the hydraulic fluid. Typically, the nitrogen escapes slowly as the membrane deteriorates over time with no way of detecting the leak. The unknown failure of the accumulator can lead to unreliable operation of the hydraulic system.
Additionally, the accumulators are often added as an afterthought in hydraulic system designs and are haphazardly mounted around the hydraulic system wherever there is room with varying degrees of success.
The invention provides a failsafe electro-hydraulic actuator that overcomes the above-mentioned problems. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.